An isotope depends on the number of neutrons in the atom. If you consider various isotopes of a particular element, the proton number does not change.
Examples:
Carbon 12: 6n, 6p
Carbon 13: 7n, 6p
Hydrogen 1 (protium): 1p
Hydrogen 2 (deuterium): 1n, 1p
There are many elements that have only one naturally occurring isotope. When you get to transuranic elements the elements all have no naturally occurring isotopes. But all elements have isotopes, they just have to be created, maybe in a nuclear reactor or particle accelerator or a supernova explosion.
No elements have the same average mass, but some isotopes are the same mass as other elements, For example Carbon-13 (an isotope of carbon) has the same mass as nitrogen-13 (which is also an isotope of nitrogen).
No.
No. Deuterium is not an element in and of itself. It is an isotope of hydrogen.
No. Only radioactive elements have half-lives, the half-life is the time that it will take for half of the atoms in a sample of a radioactive isotope to decay into another element or isotope. This is a constant property of the isotope and does not depend on the sample size. Stable isotopes never decay.
6C13 isotope. The element is carbon
By striking it with neutrons.
Deuterium is an isotope of hydrogen.
There are many elements that have only one naturally occurring isotope. When you get to transuranic elements the elements all have no naturally occurring isotopes. But all elements have isotopes, they just have to be created, maybe in a nuclear reactor or particle accelerator or a supernova explosion.
Isotope
All chemical elements (excepting the isotope 1H) contain neutrons.
The number of neutrons will vary for every isotope of an atom and is not possible to generalize for all the elements.
No elements have the same average mass, but some isotopes are the same mass as other elements, For example Carbon-13 (an isotope of carbon) has the same mass as nitrogen-13 (which is also an isotope of nitrogen).
yes. but only for a given isotope
This is an element (more exactly an isotope) which is not radioactive.
No.
Isotopes are very important part of calculations in chemistry. They are different elements of same atomic number.